Air pollution exposure and stroke: a systematic study involving more than 23 million confirms scientific evidence between gaseous air pollution and stroke.

The association between exposure to air pollution and stroke incidence and mortality has been studied and updated by a scientific analysis using more than 23 million participants.

Previous studies had already suggested that exposure to air pollution may increase the risk of stroke, but the definite scientific results were not there. Recent scientific studies have, however, shown a high connection between exposure to air pollution and the risk of stroke and subsequent mortality.

Sixty-eight studies were conducted on a sample of more than 23 million participants. Meta-analyses showed significant associations of all six air pollutants and hospitalization for stroke (e.g., PM2.5: OR = 1.008 (95% CI 1.005, 1.011); NO2: OR = 1.023 (95% CI 1.015, 1.030), per 10 μg/m3 increase in air pollutant concentration).

Exposure to PM2.5, SO2, and NO2 was associated with an increased risk of stroke incidence (PM2.5: HR = 1.048 (95% CI 1.020, 1.076); SO2: HR = 1.002 (95% CI 1.000, 1.003); NO2: HR = 1.002 (95% CI 1.000, 1.003), respectively). However, no significant differences were found in the associations of PM10, CO, O3, and stroke incidence. Except for CO and O3, we found that a higher level of air pollution exposure (PM2.5, PM10, SO2, and NO2) was associated with higher stroke mortality (eg, PM10: OR = 1.006 (95% CI 1.003, 1.010), SO2: OR = 1.006 (95% CI 1.005, 1.008).

Air pollution exposure was already associated with an increased risk of hospitalization for stroke (PM2.5, PM10, SO2, NO2, CO, and O3), incidence (PM2.5, SO2, and NO2), and mortality (PM2.5, PM10, SO2, and NO2).